The present invention is directed generally to a mechanical steering helm which can be mounted in the confined console space found on small class boats, where the helmsman has control of the boat. It is at this position wherein the single cable push-pull, flexible type steering cable originates. Normally, a steering wheel is operatively connected to a remote control head which is connected to the steering cable.
This invention pertains more specifically to a self-locking or non-reversible type of remote control steering head, one having the capability of holding a boat on a predetermined and set course. This remote control steering head will hold a boat on the last course steered to by the helmsman and will stay there should he be thrown out of the boat or become incapacitated.
In conventional mechanical helms, the steering wheel turns a shaft connected to a small spur gear which turns a larger spur gear connected to a cable sprocket for reeling in and paying out the steering cable in response to rotation of the steering wheel. The problem with the prior art arrangement is that such helms are freewheeling and susceptible to steering torque and back driving. The same problem also exists in conventional variations of the above-described mechanical helm, such as drum, rotary, or rack and pinion helm systems. Steering torque is produced by the turning of a boat propeller or by imperfections in the lower unit or outdrive or by maladjustment of the trim tab. Over the past twenty years many human lives have been lost because of the tendency of a boat with a mechanical steering helm to allow the propeller shaft torque to back drive the helm, causing steering course change.
It must be noted that with high power, high speed boats the relation of the helm to the rudder or stern drive must be in unison without any backlash or freeplay in the steering system to also eliminate chine walking, which is the rolling back and forth, port to starboard on the perimeter of the hull of the boat at the stern, and can be as life threatening as the loss of steering control.
The problem with all prior art arrangements is their adaptability to small class boats using a single cable push-pull flexible type of steering system and a remote control head. The incorporation of a worm-worm gear in the remote steering head of this invention, modifies the single cable push-pull steering system now on the market, so as to become non-reversible, or "self-locking".
All prior art pertaining to the single cable push-pull steering system, whether it be rotary or rack and pinion is reversible, although attempts have been made to eliminate back driving by placing an adjustable brake or friction device on the remote control head.
A primary object of the invention is to provide an improved remote steering system which is self-locking and non-reversible at all steering positions and not susceptible to problems of steering torque and back driving.
Another object is to provide an improved remote control steering head wherein a worm drives a worm gear in unison with a cable drive sprocket, drum or spool.
Another object is to provide an improved remote control steering head which eliminates steering torque for all trim positions of the motor or outdrive, regardless of the horsepower or type of propeller used.
Another object is to provide an improved remote control steering head which facilitates operation of a boat by physically handicapped or disabled persons.
Another object is to provide an improved remote control steering head which is safer by eliminating the tendency of a deserted boat to go into repeated looping circles.
Another object is to provide an improved remote control steering head which tends to lock an outboard or stern drive motor in its preset position during trailering of the boat, not allowing the motor to swing back and forth, possibly causing damage.
Finally, an object is to provide an improved remote control steering head which is simple and rugged in construction, easily adaptable from one boat to another, economical to manufacture, readily available as an after-market product and very easy to install by the boat owner.